5-8 September 2022
Wyndham Grand Salzburg Conference Center
Europe/Vienna timezone

Impact of process parameters during multi-step carbo-austempering on the hardness and microstructure morphology

6 Sep 2022, 14:35
Room 2

Room 2

Oral Presentation Thermochemical treatment (carburizing, carbonitriding, nitrocarburizing, nitriding) SURFACE ENGINEERING


Rainer FECHTE-HEINEN (Leibniz-Institut für Werkstofforientierte Technologien - IWT)


Highly stressed components such as gears are usually case-hardened according to the current state of the art in order to adjust the specific stressability at the tooth flank and root. The heat treatment process typically involves carburization followed by quenching to room temperature in gaseous or liquid media. In most cases, the result is a predominantly martensitic structure with finely distributed retained austenite.
In particular, an isothermal transformation of the carburized component into lower bainite promises advantages for the mechanical properties of components treated in this way due to the increased toughness of the bainite compared to the high-carbon tempered martensite. In addition, further changes in the process regarding the quenching technology for hot bath treatment due to the bainitic transformation are necessary. For example, the transformation temperature and duration must be adjusted depending on the previous carburization and the surface carbon content set in this process.
The results of the first project carried out for this purpose have already produced very promising results that have shown great potential for technical application. Open questions have arisen regarding the process duration and achievable hardness or the mechanical properties, which are currently investigated in a follow-up project, particularly with regard to a multi-stage isothermal transformation into lower bainite. In this context, extensive dilatometric and metallographic investigations were carried out to characterize the transformation kinetics and resulting phase fractions as well as their morphology.
The process and material engineering of carburization with subsequent multi-stage bainitic transformation as well as the resulting mechanical characteristic were systematically investigated and will be presented and discussed in the context of the talk.

Speaker Country Germany
Register for the Tom Bell Young Author Award (TBYAA)? No

Primary authors

Dr Holger SURM (Leibniz-Institut für Werkstofforientierte Technologien, IWT) Matthias STEINBACHER (Leibniz-Institut für Werkstofforientierte technologien)


Rainer FECHTE-HEINEN (Leibniz-Institut für Werkstofforientierte Technologien - IWT)

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